In general, coated abrasive articles have abrasive particles secured to a backing. More typically, coated abrasive articles comprise a backing having two major opposed surfaces and an abrasive layer secured to a major surface. The abrasive layer typically comprises abrasive particles and a binder, wherein the binder serves to secure the abrasive particles to the backing.
One common type of coated abrasive article has an abrasive layer comprising a make layer, a size layer, and abrasive particles. In making such a coated abrasive article, a make layer comprising a first binder precursor is applied to a major surface of the backing. Abrasive particles are then at least partially embedded into the make layer (e.g., via electrostatic coating), and the first binder precursor is cured (i.e., crosslinked) to secure the particles to the make layer. A size layer comprising a second binder precursor is then applied over the make layer and abrasive particles, followed by curing of the binder precursors. Some coated abrasive articles further comprise a supersize layer covering the abrasive layer. The supersize layer typically includes grinding aids and/or anti-loading materials.
Another common type of coated abrasive article comprises an abrasive layer secured to a major surface of a backing, wherein the abrasive layer is provided by applying a slurry comprised of binder precursor and abrasive particles onto a major surface of a backing, and then curing the binder precursor.
Some coated abrasive articles further comprise a backing treatment such as a backsize layer (i.e., a coating on the major surface of the backing opposite the major surface having the abrasive layer), a presize layer, a tie layer (i.e., a coating between the abrasive layer and the major surface to which the abrasive layer is secured), and/or a saturant. Optionally, the backing may further comprise a subsize treatment. A subsize is similar to a saturant except that it is applied to a previously treated backing.
Conventional backing treatments used in coated abrasive constructions include resole phenolic resins, phenolic/latex blends, urea-formaldehyde, and melamine formaldehyde resins. Backing treatments such as these typically exhibit good adhesion to resole phenolic, urea-formaldehyde, and epoxy based make layers and slurry layers. However since these types of backing treatments are typically only partially cured prior to the make coat application, they typically emit various volatiles such as water, phenol, and formaldehyde that can impart additional porosity to the abrasive layer, particles and/or interfere with curing of the make layer.
During use, the temperature of coated abrasives typically rises due to frictional heating. Such heating may lead to problems such as the abrasive layer separating from the backing, whether the backing is treated or not.